Manufacture of carbon composites by hot pressing
A mixture of carbon-containing fibers, such as mesophase or isotropic pitch fibers, a suitable matrix material, such as a milled pitch is compressed while resistively heating the mixture to form a carbonized composite material. Preferably, the carbonized material has a density of at least about 1.30 g/cm 3 . Preferably, the composite material is formed in less than ten minutes. This is a significantly shorter time than for conventional processes, which typically take several days and achieve a lower density material. A treating component may be impregnated into the composite. Consequently, carbon composite materials having final densities of about 1.6-1.8 g/cm 3 or higher are readily achieved with one or two infiltration cycles using a pitch or other carbonaceous material to fill voids in the composite and rebaking.
1 - 10 . (canceled)
11 . A vehicle friction brake assembly comprising:
a friction element having at least a metal surface which rotates with a wheel of a vehicle; and
a braking element having a surface aligned to movably engage said metal surface of said friction element, wherein at least said surface of said braking element comprises a carbon composite having a carbonized matrix impregnated with a treating component.
12 . The vehicle friction brake assembly according to claim 11 wherein said surface further comprises at least one of a friction additive or a performance enhancer.
13 . The vehicle friction brake assembly according to claim 12 wherein a concentration of said friction additive through a thickness of said surface comprises substantially uniform.
14 . The vehicle friction brake assembly according to claim 11 wherein said treating component comprises at least one of a metal, a thermosett material, and combinations thereof.
15 . The vehicle friction brake assembly according to claim 11 wherein said friction element comprises a brake drum or a brake rotor.
16 . The vehicle friction brake assembly according to claim 11 wherein said braking element comprises a brake pad.
17 . The vehicle friction brake assembly according to claim 11 wherein said treating component comprises a thermosett material.
18 . A method of making a vehicle friction brake assembly comprising:
rotatably attaching a friction element comprising a metal surface onto a vehicle; and
aligning a braking element to movably engage said friction element, said braking element comprising a surface comprised of a carbon composite having a carbonized matrix and a treating component, said surface of said braking element aligned to engage said metal surface.
19 . The method according to claim 18 , wherein said treating component comprises at least one of a thermosett material, a metal, a metal alloy, and combinations thereof.
20 . The method according to claim 18 , wherein said composite further comprise at least one of a friction additive or a performance enhancer.